Device and method for processing of wafers

ABSTRACT

The invention relates to a device for processing of substrates, especially wafers, with at least one pretreatment module, at least one aftertreatment module and at least one primary treatment module, and the pretreatment module and the aftertreatment module can be switched as a lock for the primary treatment module, and a corresponding method for processing of substrates, especially wafers.

RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.13/878,570, filed Apr. 10, 2013, which is a U.S. National StageApplication of International Application No. PCT/EP11/67405, filed Oct.5, 2011, which claims priority from German Patent Application No. 102010 048 043.6, filed Oct. 15, 2010, said patent applications herebyfully incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a device for processing of substrates orsubstrate pairs, especially wafers as wafer pairs.

BACKGROUND OF THE INVENTION

Process systems or process devices of semiconductor technology aregenerally of modular structure. They conventionally consist of differentchambers in which various process steps are carried out. Thus, forexample for pretreatment of wafers, process steps such as wet cleaning,plasma treatment, etching or heating can be used, while for primarytreatment of a wafer, bonding, lacquering, imprinting, embossing andexposure are possible. In known process systems the wafers or waferstacks are transported with cassettes between the process systems ormodules of process systems.

During transport, the contamination, damage, fouling or oxidation andthus influencing of other process steps can occur.

Contamination of the primary treatment chambers between treatments ofsuccessive wafers, therefore in loading and unloading of wafers, is alsoa problem.

Furthermore it is critical with respect to time that in the primarytreatment large pressure differences from atmospheric pressure as far asvery low pressures of 10⁻⁶ bar or less must be overcome.

SUMMARY OF THE INVENTION

The object of this invention is therefore to optimize the processing ofsubstrates both in terms of the sequence, and also to avoidcontamination, damage, fouling or oxidation as much as possible.

This object is achieved with the features of the independent claims.Advantageous developments of the invention are given in the dependentclaims. All combinations of at least two of the features given in thespecification, the claims and/or the figures also fall within theframework of the invention. At the given value ranges, values within theindicated limits will also be disclosed as boundary values and will beclaimed in any combination.

The invention is based on the idea of coupling a primary treatmentmodule to at least one pretreatment module and at least oneaftertreatment module such that at least one of the pretreatment modulesand at least one of the aftertreatment modules and/or the primarytreatment module each act as vacuum-tight locks for an adjacentpretreatment module, primary treatment module or aftertreatment module.At the same time, according to the invention in one embodiment of theinvention it is provided that at least one of the pretreatment modulesand/or the primary treatment module and/or at least one of theaftertreatment modules can be especially exposed to pressure, a vacuum,and/or can be temperature-treated, especially can be heatedindependently or regardless of an adjacent module.

In this way, in spite of a flexible structure of the process systemaccording to the device as claimed in the invention a time-optimized,even parallel processing of several substrates is provided within thedevice as claimed in the invention, in which based on the lock-likecoupling of the individual process modules contamination, damage,fouling or oxidation by decoupling of the substrates from externaleffects, especially in the loading and unloading of the individualmodules, is resolved.

It is especially advantageous if the primary treatment module can beloaded and unloaded exclusively via locks or a positing system. This isachieved as claimed in the invention by there being both a pretreatmentmodule which is coupled in the manner of a lock to the primary treatmentmodule and also an aftertreatment module which is coupled in the mannerof a lock to the primary treatment module. By this measure the generallyespecially critical primary treatment of the substrates or wafers whichoccurs under often extreme conditions does not take place at any instantof the processing nor during the loading and unloading of the primarytreatment module with contact with the environment. The primarytreatment module is accordingly completely decoupled from theenvironment so that contamination, damage, fouling or oxidation duringthe primary treatment of the substrates is essentially precluded.Furthermore, there is the advantage that the steps preparatory andsubsequent to primary treatment can be moved into the pretreatmentmodule and the aftertreatment module, especially at least partialexposure to pressure and/or temperature. In the primary treatment moduleas a result of this only a lower pressure difference and/or temperaturedifference than from the ambient/atmospheric pressure p_(ATM) need beovercome.

According to one advantageous embodiment of the invention, it isprovided that the primary treatment chamber can be switched as a lock inthe loading and unloading of the substrates. Thus, when the primarytreatment chamber is being loaded, at the same time aftertreatment ofthe substrate which has been worked beforehand in the primary treatmentchamber can take place. When the primary treatment chamber is beingunloaded, conversely at the same time pretreatment of the next substratewhich is to be worked in the primary treatment chamber can take place inthe pretreatment chamber.

In another advantageous embodiment, it is provided that the pretreatmentchamber and/or the primary treatment chamber and/or the aftertreatmentchamber can be heated especially separately by means of a heatingapparatus. It is especially advantageous here if the pretreatmentchamber and/or the primary treatment chamber and/or the aftertreatmentchamber are completely heat-insulated. In this way exact temperaturecontrol is possible with heat loss as low as possible.

To the extent other correspondingly made pretreatment modules can beconnected upstream to the pretreatment module as locks and/or othercorrespondingly made aftertreatment modules can be connected downstreamof the aftertreatment module as locks, the method sequence can befurther subdivided so that optimization of the passage times in theprocess sequence arises. Here it is conceivable as claimed in theinvention that at the same time several pretreatment modules aredirectly coupled to one pretreatment module via lock doors. In this waytime-intensive pretreatment steps can proceed parallel and accordinglystaggered in time in the upstream pretreatment modules. This appliesanalogously to the corresponding aftertreatment modules.

By the locks being made as pressure locks and/or temperature locks it ispossible as claimed in the invention to control the pressure and/or thetemperature by corresponding switching of the pretreatment modulesand/or the aftertreatment modules.

For loading and unloading, as claimed in the invention there is aloading and unloading apparatus, especially at least one robot arm. Thelatter is used for loading and unloading of the substrates into/out ofthe primary treatment chamber and/or the pretreatment chamber and/or theaftertreatment chamber, and for parallel handling there can be severalsubstrates/wafers in the process sequence, as claimed in the inventionseveral robot arms. Thus for example in each pretreatment chamber and/oreach aftertreatment chamber there can be exactly one robot arm which canengage the respectively adjacent pretreatment chamber and/or primarytreatment chamber for loading and unloading of the respectively adjacentchambers when the respective lock door is opened.

According to one especially advantageous embodiment of the invention itis provided that the primary treatment chamber can be loaded at the sametime from the pretreatment chamber and can be unloaded into theaftertreatment chamber and/or the pretreatment chamber and theaftertreatment chamber can be loaded at the same time via the first lockdoor and unloaded via the second lock door.

Other advantages, features and details of the invention will becomeapparent from the following description of preferred exemplaryembodiments and using the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a schematic plan view of a device as claimed in theinvention with a pretreatment module, a primary treatment module and anaftertreatment module.

FIG. 1 b shows a schematic sectional view of the device as claimed inthe invention according to cutting line A-A from FIG. 1 a,

FIG. 2 a shows a schematic plan view of a second embodiment of thedevice as claimed in the invention with a pretreatment module, a primarytreatment module and an aftertreatment module,

FIG. 2 b shows a schematic sectional view of the device as claimed inthe invention according to cutting line A-A from FIG. 2 a,

FIG. 2 c shows a schematic sectional view of the device as claimed inthe invention according to cutting line B-B from FIG. 2 a,

FIG. 3 shows a pressure/temperature diagram of a method as claimed inthe invention for processing of substrates and

FIG. 4 shows a sectional view of the device as claimed in the inventionwith a pretreatment module, a primary treatment module and anaftertreatment module.

The same reference numbers for corresponding components are provided inthe figures.

DETAILED DESCRIPTION OF THE INVENTION

In the embodiment of a device 1 as claimed in the invention shown inFIG. 1 a pretreatment module 9, a primary treatment module 10 and anaftertreatment module 11 are arranged linearly in a row.

The pretreatment module 9 consists of a pretreatment chamber 2 which canbe exposed to a vacuum and which surrounds a pretreatment space 12. Apressurization apparatus which is not shown is connected to thepretreatment chamber 2 and can be controlled by a central controlapparatus which is not shown in order to be able to control the pressurein the pretreatment space 12 with the pretreatment chamber 2 closed. Viaa temperature exposure apparatus which is not shown, the pretreatmentspace 12 can be heated and/or cooled, the temperature exposure apparatusbeing controllable by the central control apparatus.

To load the pretreatment module 9 with one (or more) wafers 15,according to FIG. 4 there is a first robot arm 16. The latter,controlled from the central control apparatus, can be routed through afirst lock door 5 when the first lock door 5 is opened. Opening andclosing of the first lock door 5 are likewise controlled by the centralcontrol apparatus.

The first lock door 5 in the embodiment according to FIG. 1 a and 1 b islocated on a first face side 18 of the device 1. The first lock door 5can be closed pressure-tight and has heat insulation so that thepretreatment space 12 in the closed state of the first lock door 5 canbe pressurized.

Furthermore, the pretreatment chamber 2 opposite the first lock door 5jointly with a primary treatment chamber 3 of the primary treatmentmodule 10 has a first primary lock door 6. The first primary lock door 6is made functionally analogous to the first lock door 5. The primarytreatment module 10 can be coupled pressure-tight on the first primarylock door 6 to the pretreatment modules 9, as a result of which amodular structure and a replacement of individual modules 9, 10, 11 ofthe device 1 can be implemented.

By controlling the first lock door 5 and the first primary lock door 6by means of the central control apparatus the pretreatment module 9 canbe used as a lock, specifically by the first lock door 5 being closedwhen the first lock door 6 is opened and vice versa.

The primary treatment module 10 consists of the primary treatmentchamber 3 which encloses or forms a primary treatment space 13.

Opposite the first primary lock door 6 of the primary treatment chamber3 there is a second primary lock door 7 which is included at leastpartially in the primary treatment chamber 3 and which is used to unloadthe wafer 15 from the primary treatment chamber 3 into an aftertreatmentchamber 4. The second primary lock door 7 is formed at least partiallyby the aftertreatment chamber 4. The primary treatment space 13 can besealed pressure-tight by the second primary lock door 7 from oneaftertreatment space 14 of the aftertreatment chamber 4. Functionallythe second primary lock door 7 corresponds to the first primary lockdoor 6, the first primary lock door 6 and the second primary lock door7, controlled from the central control apparatus, forming a lock.

The aftertreatment module 11 for aftertreatment of the wafer 15 afterprimary treatment in the primary treatment module 10 consists of theaftertreatment chamber 4 which forms the aftertreatment space 14.Furthermore the aftertreatment chamber 4 has a second lock door 8 whichis located opposite the second primary lock door 7.

The wafer 15 can be unloaded via the second lock door 8 and by means ofa second robot arm 17 after aftertreatment out of the aftertreatmentspace 14 as soon as the second lock door 8 is opened.

The aftertreatment module 11 can likewise act as a lock by the secondprimary lock door 7 being closed when the second lock door 8 is openedand vice versa.

The second lock door 8 is located on a second face side 19 of the device1 so that a linear movement of the wafer 15 takes place during theentire process sequence through the pretreatment module 9, the primarytreatment module 10 and the aftertreatment module 11.

The embodiment according to FIG. 2 a differs by the angular arrangementof the modules 9, 10, 11 so that an altered device 1′ results. Only theconfiguration of the primary treatment chamber 3′ is altered, since thesecond primary lock door 7 is not located opposite the first primarylock door 6, but on one side wall of the primary treatment chamber 3′.

In another embodiment of the invention, in the embodiment according toFIGS. 1 a and 1 b an additional side module (not shown) analogously tothe aftertreatment module 11 in FIG. 2 a can be located laterally on theprimary treatment module 10 in order to remove the damaged wafers whichare detected during the process flow from the process sequence.

A process sequence as claimed in the invention whose pressure andtemperature behavior is shown in FIG. 3 proceeds as follows:

The first primary lock door 6 and the second primary lock door 7 areclosed. Afterwards the pressure in the primary treatment space 13 islowered by a pressurization apparatus which is not shown, for example avacuum pump, especially to a pressure p_(min) less than 10⁻⁶ bar,preferably to a pressure less than 10⁻⁹ bar. This ideally takes placeonly a single time during the processing of a plurality, especially morethan 100, preferably more than 1000, even more preferably more than10000 wafers or wafer pairs.

Via the opened first lock door 5 a wafer 15 or wafer pair is loaded intothe pretreatment chamber by means of the first robot arm 16 and istreated there. Pretreatment can be a dry and/or wet process step, forexample wet cleaning, plasma treatment, etching, heating or the like.The pretreatment especially preferably comprises an especially opticaland/or mechanical alignment apparatus.

Before or after or during the pretreatment step the pretreatment space12 can be evacuated via a separately activated pressurization apparatus.

Before opening the first primary lock door 6, in any case the first lockdoor 5 is closed and the pretreatment space 12 is evacuated, especiallyto a pressure p_(V), during or shortly prior to the loading of thepretreatment chamber 3 of less than 10⁻⁶ bar, preferably less than 10 ⁻⁷bar, so that the pretreatment module 9 acts as a lock for the primarytreatment module 10.

The wafer 15 is loaded by an internal transport system, for example arobot arm, through the first primary lock door 6 into the primarytreatment chamber 3, 3′.

Then the first primary lock door 6 is closed. During the loading of theprimary treatment chamber 3, 3′ the second primary lock door 7 iscontinually closed. The pressure is preferably further lowered top_(min) less than 10⁻⁶ bar, even more preferably 10⁻⁹ bar.

After closing the first primary lock door 6, another wafer 15 can beloaded into the pretreatment chamber 2. At the same time the primarytreatment of the first wafer 15 takes place in the primary treatmentmodule 10. This can be for example bonding, lacquering, imprinting,embossing and/or exposure.

After the primary treatment of the wafer 15 in the primary treatmentmodule 10, the wafer 15 is loaded into the aftertreatment module 11 byopening the second primary lock door 7, the second lock door 8 beingclosed. Before opening of the second primary lock door 7 theaftertreatment space 14 is exposed to a vacuum, especially a pressurep_(N) of less than 10⁻⁶, preferably less than 10⁻⁷ by a pressurizationapparatus of the aftertreatment module 11 at least until the wafer 15 isloaded from the primary treatment module 10 into the aftertreatmentmodule 11 and the second primary lock door 7 is closed again.

Then aftertreatment of the wafer 15 takes place in the aftertreatmentmodule 11, for example cooling and simultaneous raising of the pressureby the pressurization apparatus of the aftertreatment module 11.

After completion of the aftertreatment of the wafer 15 in theaftertreatment module 11, the wafer 15 is removed via the second lockdoor 8 and the second robot arm 17.

Before each opening of the primary lock door 6 the pretreatment chamber2, and before each opening of the primary lock door 7 the aftertreatmentchamber 4 are exposed to a pressure p_(V) or p_(N) less than theatmospheric and/or ambient pressure P_(ATM) outside the chambers 2, 3, 4and/or decontaminated, especially flushed with inert gas.

According to one especially advantageous embodiment of the abovedescribed invention, the wafer 15 is a wafer pair and a wafer pair isloaded into the device 1 in the above described manner by means of aholding device or handling apparatus for handling of the wafer pair, thepretreatment shown in the left-hand section in FIG. 3 comprising thesteps heating, evacuation, gas flushing with reducing gas, a wetchemical treatment, a plasma treatment and/or argon bombardment.

The primary treatment takes place in a vacuum which is higher comparedto pretreatment, therefore at a lower pressure p_(min) as is shown inFIG. 3 in the middle section. A controlled gas atmosphere, therefore anexactly set gas pressure and an exactly controlled mixing ratio of gasesare set by the pressurization apparatus of the primary treatment module10. Then the wafer pair is brought into contact and bonded. Beforehand,the temperature which is necessary for the joining, especially T_(max),is set to be greater than 250° C., preferably T_(max) greater than 400°C. During bonding, a force as uniform as possible is applied to thewafer pair and/or an electrical voltage is applied.

The aftertreatment which is shown in FIG. 3 in the right-hand section,takes place in an nonoxidizing environment, in which cooling takes placeand the pressure is raised to atmospheric pressure. Slow coolingprevents or avoids thermal stresses in the wafer pair which was bondedbeforehand.

The pretreatment of the wafer pair can take place according to oneembodiment such that there are a first pretreatment module forpretreatment of the first wafer or wafer pair and a second pretreatmentmodule for pretreatment of the second wafer or wafer pair. The first andthe second wafer can be loaded into the primary treatment chamber viaseparate lock doors.

The chambers 2, 3, 4 are preferably made of stainless steel or aluminum.

In the embodiment shown in FIG. 4, the first lock door 5 is not locatedon the face side 18 of the pretreatment chamber 2′, but on the sidewall. The second lock door 8 is not located on the face side 19, but onthe side wall of the aftertreatment chamber 4′.

The process flow is shown by arrows in FIG. 4.

The primary lock doors 6, 7 must accordingly have high pressuretightness up to p_(min) and are preferably made as a transfer valvewhich is or can be inserted in a common channel between the respectivelyadjacent chambers 2, 3, 4, forming a seal. The opening diameter of thelock doors 5, 6, 7, 8 is more than 200 min, especially more than 300 mm,preferably more than 450 mm.

REFERENCE NUMBER LIST

-   1, 1′ device-   2, 2′ pretreatment chamber-   3, 3′ primary treatment chamber-   4, 4′ aftertreatment chamber-   5 first lock door-   6 first primary lock door-   7 second primary lock door-   8 second lock door-   9 pretreatment module-   10 primary treatment module-   11 aftertreatment module-   12 pretreatment space-   13 primary treatment space-   14 aftertreatment space-   15 wafer-   16 first robot arm-   17 second robot arm-   18 first face side-   19 second face side

Having described the invention, the following is claimed:
 1. A devicefor processing substrates or substrate pairs with at least onepretreatment module and at least one aftertreatment module, thepretreatment module and the aftertreatment module coupled to a maintreatment module such that the main treatment module definesvacuum-tight locks for the adjacent pretreatment module and/or theadjacent aftertreatment module.
 2. The device according to claim 1,wherein a main treatment chamber of the main treatment module can beswitched as a lock during the loading and unloading of the substrateinto the device.
 3. The device according to claim 1, wherein apretreatment chamber of the pretreatment module and/or a main treatmentchamber of the main treatment module and/or an aftertreatment chamber ofthe aftertreatment module, can be heated or cooled off by means of atemperature exposure apparatus.
 4. The device according to claim 1,wherein additional pretreatment modules are connected upstream of afirst pretreatment module as locks and/or additional aftertreatmentmodules are connected downstream of a first aftertreatment module aslocks.
 5. The device according to claim 1, wherein the locks are formedas pressure and/or temperature locks.
 6. The device according to claim1, wherein a loading and unloading apparatus is provided for loading andunloading of the substrates into/from the pretreatment module and/or theaftertreatment module.
 7. The device according to claim 3, wherein thepretreatment chamber and/or the main treatment chamber and/or theaftertreatment chamber can be heated or cooled separately.
 8. The deviceaccording to claim 6, wherein the loading and unloading apparatus is atleast one robot arm.